JP4959663B2 - Aqueous cosmetic and method for producing the same - Google Patents

Description

  The present invention relates to an aqueous cosmetic and a method for producing the same.

Ceramide exists in the stratum corneum of the skin and plays an important role in building a lipid barrier necessary for water retention and maintaining water. Ceramide in the stratum corneum is produced by cerebroside degradation by an enzyme called cerebrosidase. It is known that a part of ceramide is converted to phytosphingosine and sphingosine by an enzyme called ceramidase and is important as a regulator of cell growth and differentiation. There are seven different types of ceramide in human skin, each with a different function.
However, ceramide is a highly crystalline substance, has low solubility in other oils, and precipitates crystals at low temperatures, so it is difficult to ensure stability when blended into cosmetics. there were. In addition, it is possible to disperse the aqueous ceramide dispersion using a surfactant or the like, but it is difficult to sufficiently reduce the particle diameter, and the dispersion may lack transparency. .

As a composition containing ceramides, an emulsified composition containing a specific glycosphingolipid group having a moisturizing action, a rough skin preventing action and an emulsifying action is disclosed (for example, see Patent Document 1).
In addition, as a ceramide-containing cosmetic additive containing cholesterol, fatty acid, and water-soluble polymer (see, for example, Patent Document 2), or an external composition having excellent stability and good usability even when temperature changes are severe. In addition, a water-in-oil emulsion composition (for example, see Patent Document 3) is disclosed in which a salt formed from sphingosine and a specific fatty acid is used as an emulsifier, and an oil-soluble antioxidant is added at a specific ratio. Yes.
In addition, as a formulation technology, there is a method for producing a cosmetic additive in which a coarse dispersion of a glycosphingolipid is subjected to micronization treatment using a predetermined jet flow in order to sufficiently exert the emollient effect of the glycosphingolipid. It is disclosed (for example, see Patent Document 4).

  On the other hand, as a technique for solubilizing ceramides transparently and stably blending them, blending a specific fatty acid or a specific surfactant is disclosed (for example, see Patent Documents 5 and 6). However, as described above, since ceramide has high crystallinity, even when a stable water-emulsified dispersion is prepared, when mixed with general cosmetic ingredients, it often causes emulsion or precipitates. It was. In particular, when ceramide is stabilized with a fatty acid, cosmetic ingredients that can be blended together are limited, and the blending concentration in the final cosmetic composition has to be lowered.

In addition, regarding blending fatty acids and ceramides in cosmetics, technical and prescription design guidelines for blending particles containing ceramides in cosmetics at a high concentration with the particle size still small are still provided. There is no current situation.
JP 2000-51676 A JP-A-7-187987 JP 2006-335692 A JP-A-11-310512 JP 2001-139796 A JP 2001-316217 A

  An object of the present invention is to provide an aqueous cosmetic material in which ceramide-containing particles having a minute particle diameter are stably dispersed and excellent in stability over time, and a method for producing the aqueous cosmetic material.

Specific means for solving the above problems are as follows.
<1> Ceramides-containing particles containing at least ceramides (excluding glycosphingolipids extracted from konjac koji) and having a volume average particle diameter of 2 nm to 150 nm dispersed in an aqueous phase as an oil phase component And a fatty acid having 10 to 30 carbon atoms or a salt thereof, and an electrolyte, a pH of 6.5 or more, and an electrical conductivity of 5.0 mS / cm or less.
<2> The aqueous cosmetic according to <1>, wherein the pH and the electrical conductivity (mS / cm) satisfy the relationship of the following formula (A).
Conductivity (mS / cm) ≦ 2.2 × pH-7 Formula (A)
<3> The aqueous cosmetic according to <1> or <2>, wherein the particles have a volume average particle diameter of 5 nm to 100 nm.
<4> The aqueous cosmetic according to any one of <1> to <3>, further comprising a polyhydric alcohol.
<5> The aqueous cosmetic according to any one of <1> to <4>, further comprising a polymer compound.
<6> The aqueous cosmetic according to any one of <1> to <5>, wherein the fatty acid having 10 to 30 carbon atoms is liquid at 30 ° C.
<7> The fatty acid having 10 to 30 carbon atoms or a salt thereof is at least one selected from the group consisting of lauric acid, isostearic acid, oleic acid, γ-linolenic acid, α-linolenic acid, and salts thereof < The aqueous cosmetic according to any one of 1> to <6>.
<8> The method for producing an aqueous cosmetic according to any one of <1> to <7>,
Mixing an oil phase component containing at least the ceramide and an aqueous phase component at a temperature of 40 ° C. or lower to obtain a ceramide dispersion;
Mixing the ceramide dispersion with an aqueous composition;
A method for producing a water-based cosmetic comprising:
<9> The method for producing an aqueous cosmetic according to <8>, comprising dissolving the ceramides in a good solvent for ceramides.
<10> The method for producing an aqueous cosmetic according to <9>, wherein the good solvent of the ceramide is a water-soluble organic solvent.
<11> The mixture of the oil phase component and the water phase component is mixed and mixed after passing through the microchannels having the narrowest cross-sectional area of 1 μm ² or more and 1 mm ² or less independently. The method for producing an aqueous cosmetic according to any one of <8> to <10>.

  ADVANTAGE OF THE INVENTION According to this invention, the ceramides containing particle | grains which have a very small particle diameter can be stably disperse | distributed, and the aqueous cosmetics excellent in stability with time, and the manufacturing method of this aqueous cosmetics can be provided.

The aqueous cosmetic composition of the present invention contains at least ceramides, ceramide-containing particles having a volume average particle diameter of 2 nm to 150 nm and dispersed in an aqueous phase as an oil phase component, and a fatty acid having 10 to 30 carbon atoms or It contains at least the salt and an electrolyte, has a pH of 6.5 or more, and an electrical conductivity of 5.0 mS / cm or less.

The pH and conductivity in the aqueous cosmetic of the present invention preferably further satisfy the relationship of the following formula (A), more preferably satisfy the relationship of the following formula (B), and the relationship of the following formula (C): It is more preferable to satisfy.
Conductivity (mS / cm) ≦ 2.2 × pH-7 Formula (A)
Conductivity (mS / cm) ≦ 2.2 × pH-9 Formula (B)
Conductivity (mS / cm) ≦ 2.2 × pH-11 Formula (C)

  In the aqueous cosmetic composition of the present invention having such characteristics, the ceramide-containing particles can be stably dispersed in the system and can exhibit good temporal stability.

As in the case of the aqueous cosmetic of the present invention, the aqueous cosmetic containing the ceramide-containing particles and the fatty acid component as essential components may impair stability over time when the pH of the system is low. This is because the fatty acid component contained in the aqueous cosmetics functions as a dispersant for the ceramide-containing particles and exhibits excellent dispersibility, but when the pH is low, the fatty acid contained in the system It is presumed that the dispersibility and stability of the ceramide-containing particles are hindered due to an increase in the number of components in a non-dissociated state (—COOH). For this reason, in a low pH region, if the electrolyte concentration is high, the stability tends to be further deteriorated. Therefore, it is necessary to suppress the salt concentration in the cosmetic to an extremely low level.
On the other hand, in the region where the pH is high, since the fatty acid component contained in the aqueous cosmetic composition of the present invention is in a dissociated state (—COO ⁻ ), there is an electrostatic repulsion between the ceramide-containing particles. It tends to be stronger and the dispersion stability tends to improve. Therefore, if the pH of the aqueous cosmetic is high, even if the salt concentration in the aqueous cosmetic is high to some extent, the dispersibility and stability of the ceramide-containing particles can be achieved. Thus, it can be said that the pH and electrolyte concentration exhibited by the aqueous cosmetic containing the ceramide-containing particles and the fatty acid component greatly contribute to the dispersibility and stability of the ceramide-containing particles.
Moreover, when there is much content about the electrolyte which aqueous cosmetics contain, the electrical conductivity which the said cosmetics show will become high.
In view of the above matters, the present inventors have studied by paying attention to pH and conductivity in an aqueous cosmetic containing ceramide-containing particles, a fatty acid component, and an electrolyte. The electrical conductivity has a correlation with the dispersibility and stability of the ceramide-containing particles, and the ceramide-containing particles are stably dispersed within the range of the pH and conductivity, and the stability over time is also excellent. Has been found to be a water-based cosmetic.

In the aqueous cosmetic of the present invention, the pH and conductivity having the above relationship will be further described.
Aqueous cosmetic preparation of the present invention, shows a pH of 5.5 or more, more preferably 6.0 or more as the pH, and most preferably 6.5 or more. It is preferable that the pH is 5.5 because the occurrence of turbidity due to the generation of precipitates and suspended matters in cosmetics and the coarsening due to aggregation of ceramide-containing particles is more effectively suppressed. Further, the upper limit of the pH is preferably 10.0 or less, more preferably 9.0 or less, and more preferably 8.5 or less from the viewpoint of reducing irritation when the cosmetic is applied to the skin. Most preferably:

The pH of the aqueous cosmetic of the present invention can be adjusted with a base / acid. When adjusting the pH of the aqueous cosmetic, it can be set by adjusting the amount of acid usually used in cosmetics such as hydrochloric acid, citric acid, lactic acid and glutamic acid and a base such as sodium hydroxide and arginine.
The pH in the present invention is a value measured by the glass electrode method.

Aqueous cosmetic preparation of the present invention, shows a 5.0 mS / cm or less in electric conductivity (mS / cm), as the electric Shirubedo, more preferably at most 3.0 mS / cm, 2.0 mS / cm Most preferably: When the electrical conductivity is 5.0 mS / cm or less, the occurrence of turbidity due to the generation of precipitates and suspended matters in cosmetics and the coarsening due to aggregation of ceramide-containing particles is more effectively suppressed. Therefore, it is preferable.

  The electric conductivity in the present invention is a value measured by the AC two-electrode method.

  The aqueous cosmetic of the present invention takes a form in which ceramide-containing particles are dispersed in an aqueous phase as an oil phase component. Here, the ceramide-containing particles in the present invention contained as an oil phase component may be liquid or solid at room temperature as long as it has a particle size within the range specified in the present invention, It may be dissolved or dispersed in other oily components.

  In addition, an aqueous solution mainly composed of an aqueous medium such as water can be used for the aqueous phase, which is a dispersion medium in which ceramide-containing particles are dispersed, and other than water, polyhydric alcohol and the effects of the present invention are not impaired. It is possible to further add water-soluble functional ingredients such as a range of water-soluble antioxidants and plant extracts.

  Hereinafter, each component contained in the aqueous cosmetic of the present invention will be described in more detail.

(1) Ceramides-containing particles The ceramides-containing particles in the present invention are particles having a volume average particle diameter of 2 nm or more and 150 nm or less, which contains at least ceramides and is dispersed in an aqueous phase as an oil phase component.

  The ceramides in the present invention include ceramide and derivatives thereof, and the origin of synthetic products, extracts and the like is not limited. The “ceramides” in the present invention include natural ceramides described later and compounds having the same as a basic skeleton, and precursors from which these compounds can be derived, and include sugar-modified ceramides such as natural ceramides and glycosphingolipids. , Ceramide analogs, sphingosine and phytosphingosine, and their derivatives. Hereinafter, the ceramides in the present invention will be described in detail.

(Natural ceramide)
In the present invention, the natural ceramide means a ceramide having the same structure as that present in the human stratum corneum. A more preferred embodiment of the natural ceramide is an embodiment that does not include glycosphingolipid and has 3 or more hydroxyl groups in its molecular structure.
Hereinafter, the natural ceramide usable in the present invention will be described in detail.

Examples of the basic structural formula of natural ceramide that can be suitably used in the present invention are shown in the following (1-1) to (1-9).
(1-1) is ceramide 1, (1-2) is ceramide 9, (1-3) is ceramide 4, (1-4) is ceramide 2, (1-5) is ceramide 3, (1-6) Is a compound known as ceramide 5, (1-7) is ceramide 6, (1-8) is ceramide 7, and (1-9) is a compound known as ceramide 8.

The above structural formula shows an example of each ceramide, but since it is a natural product, ceramides actually derived from humans and animals have various variations in the length of the alkyl chain. As long as it has the skeleton, the alkyl chain length may be any structure.
In addition, ceramides modified according to the purpose, such as introducing a double bond in the molecule to impart solubility or introducing a hydrophobic group to impart permeability Can also be used.

These ceramides having a general structure called a natural type are natural products (extracts) and those obtained by microbial fermentation, but may further contain synthetic products and animals.
These ceramides use natural (D (-)) optically active substances, but if necessary, non-natural (L (+)) optically active substances can be used to further reduce natural and non-naturally-occurring forms. Natural type mixtures may be used. The relative configuration of the above compound may be a natural configuration, a non-natural configuration other than that, or a mixture thereof.
When the aqueous cosmetic composition of the present invention is used for purposes such as skin emollient, it is preferable to use more natural optically active substances from the viewpoint of the barrier effect.

  Such natural type ceramide is also available as a commercial product. For example, Ceramide I, Ceramide III, Ceramide IIIA, Ceramide IIIB, Ceramide IIIC, Ceramide VI (above, manufactured by Cosmo Farm), Ceramide TIC-001 ( Takasago Inc.), CERAMIDE II (Quest International), DS-Ceramide VI, DS-CLA-Phytoceramide, C6-Phytoceramide, DS-ceramide Y3S (DOOSAN), CERAMIDE2 (Cedera) In addition, the exemplified compound (1-5) is “ceramide 3” (trade name, manufactured by Evonik (former Degussa)), and the exemplified compound (1-7) is “ceramide 6” (trade name, Evonik). (Former Degussa)].

  The natural ceramide contained in the ceramide-containing particles may be a single type or a combination of two or more types. However, since ceramides generally have a high melting point and high crystallinity, From the viewpoint of emulsion stability and handleability, it is preferable.

(Sugar-modified ceramide)
Sugar-modified ceramide is a ceramide compound containing a saccharide in the molecule. Examples of the saccharide contained in the ceramide compound molecule include monosaccharides such as glucose and galactose, disaccharides such as lactose and maltose, and oligosaccharides obtained by polymerizing these monosaccharides and disaccharides by glucoside bonds. Examples include saccharides and polysaccharides. The saccharide may be a saccharide derivative in which the hydroxyl group in the saccharide unit is replaced with another group. Examples of such sugar derivatives include glucosamine, cururonic acid, and N-acetylglucosamine.
Among these, from the viewpoint of dispersion stability, saccharides having 1 to 5 saccharide units are preferable. Specifically, glucose and lactose are preferable, and glucose is more preferable.
Specific examples of the sugar-modified ceramide include the following.

  The sugar-modified ceramide can be obtained by synthesis or as a commercial product. For example, the exemplary compound (4-1) is available as Okayasu Shoten, “comesfingo glycolipid” (trade name).

(Ceramide analogue)
A ceramide analog is synthesized by imitating the structure of ceramide. As a known compound of such a ceramide analog, for example, a ceramide analog as shown in the following structural formula can also be used.

  When applying a ceramide analog, for example, from the viewpoint of the feeling of use and moisturizing of the aqueous cosmetic composition of the present invention, it is preferably an analog of natural ceramide or sugar-modified ceramide, and an analog of natural ceramide It is more preferable that

(Sphingosine, phytosphingosine)
As sphingosine and phytosphingosine, natural sphingosine and sphingosine analogs can be used regardless of whether they are synthetic products or natural products.

Specific examples of natural sphingosine include sphingosine, dihydrosphingosine, phytosphingosine, sphingadienin, dehydrosphingosine, dehydrophytosphingosine, and their N-alkyl (eg, N-methyl), acetylated compounds, and the like. Is mentioned.
These sphingosines may be either natural (D (−)) optically active or non-natural (L (+)) optically active, or a mixture of natural and non-natural types. May be used. The relative configuration of the above compound may be a natural configuration, a non-natural configuration other than that, or a mixture thereof. Specific examples include PHYTOSPHINGOSINE (INCI name: 8th Edition) and exemplified compounds described below.

As phytosphingosine, either an extract from nature or a synthetic product may be used. It can also be obtained as a commercial product by synthesis.
Examples of commercially available natural sphingosines include D-Sphingosine (4-Sphingenine) (SIGMA-ALDRICH), DSphytosphingosine (DOOSAN), phytosphingosine (Cosmo Farm), and the exemplified compounds ( 5-5) is available from Evonik (formerly Degussa) as “Phytosphingosine” (trade name).

-Acid-
In the present invention, when sphingosines such as sphingosine and phytosphingosine are used, it is preferable to use a compound having an acidic residue capable of forming a salt with the compound. As the compound having an acidic residue, an inorganic acid or an organic acid having 5 or less carbon atoms is preferable.
Examples of the inorganic acid include phosphoric acid, hydrochloric acid, nitric acid, sulfuric acid, perchloric acid, carbonic acid and the like, and phosphoric acid and hydrochloric acid are preferable.
Examples of organic acids include monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, and valeric acid; dicarboxylic acids such as succinic acid, phthalic acid, fumaric acid, oxalic acid, malonic acid, and glutaric acid; glycolic acid, Examples thereof include oxycarboxylic 40 acids such as citric acid, lactic acid, pyruvic acid, malic acid and tartaric acid; amino acids such as glutamic acid and aspartic acid. As these compounds, phosphoric acid, hydrochloric acid, succinic acid, citric acid, lactic acid, glutamic acid, aspartic acid and the like are preferable, and lactic acid, glutamic acid, aspartic acid and the like are particularly preferable.
The acid used in combination may be used in combination with sphingosines in advance, or may be added when the ceramide analog-containing particles are formed, or may be added and used as a pH adjuster after the formation of the ceramide-containing particles. .
When the acid is used in combination, the amount added is preferably about 1 to 50 parts by mass with respect to 100 parts by mass of the sphingosine used.

-Content of ceramides-
From the viewpoint of efficient absorption of the ceramide component from the skin when using the aqueous cosmetic composition of the present invention and expectation of expression of the effect due to ceramide, the oil component contained in the oil phase in the ceramide-containing particles It is more preferable to contain 20% by mass or more and 100% by mass or less of ceramides, and still more preferable to contain 30% by mass or more and 100% by mass or less. Thus, the natural ceramide content is preferably 30% by mass or more with respect to the total mass of the ceramides, from the viewpoint of expectation of the effect of the natural ceramide, and most preferably 100% by mass.

  The content of ceramides in the aqueous cosmetic composition of the present invention is preferably in the range of 0.001% by mass to 5% by mass, and in the range of 0.01% by mass to 3% by mass. More preferable. By containing the ceramides in the above range in the aqueous cosmetic, the moisture retention and barrier function recovery effect of the aqueous cosmetic of the present invention can be obtained.

-Particle size-
The ceramide-containing particles have a volume average particle size of 2 nm to 150 nm, preferably 3 nm to 150 nm, more preferably 5 nm to 120 nm, and most preferably 5 nm to 100 nm.
By making the particle size of the ceramide-containing particles 3 nm or more and 150 nm or less, the transparency of the water-based cosmetic is ensured, and the effects desired for the water-based cosmetic such as skin permeability are satisfactorily exhibited. Can do.

The particle size of the ceramide-containing particles can be measured with a commercially available particle size distribution meter or the like.
Particle size distribution measurement methods include optical microscopy, confocal laser microscopy, electron microscopy, atomic force microscopy, static light scattering, laser diffraction, dynamic light scattering, centrifugal sedimentation, and electrical pulse measurement. Methods, chromatographic methods, ultrasonic attenuation methods and the like are known, and devices corresponding to the respective principles are commercially available.

  In the particle size measurement of the ceramide-containing particles in the present invention, it is preferable to apply a dynamic light scattering method from the particle size range and ease of measurement. As a commercially available measuring device using dynamic light scattering, Nanotrac UPA (Nikkiso Co., Ltd.), dynamic light scattering type particle size distribution measuring device LB-550 (Horiba, Ltd.), a concentrated particle size analyzer FPAR-1000 (Otsuka Electronics Co., Ltd.) etc. are mentioned.

The particle size of the ceramide-containing particles in the present invention is a value measured using a dynamic light scattering particle size distribution analyzer LB-550 (Horiba, Ltd.). Specifically, the particle size is measured as follows. Adopt the value.
That is, the method for measuring the particle size of the ceramide-containing particles is obtained by diluting with pure water so that the concentration of the oil component contained in the sample taken from the aqueous cosmetic of the present invention is 1% by mass, To make measurements. The particle diameter can be obtained as the median diameter when the sample refractive index is 1.600, the dispersion medium refractive index is 1.333 (pure water), and the viscosity of the pure water is set as the viscosity of the dispersion medium.

  Forms of the ceramide-containing particles include 1) the ceramide-containing particles (oil phase) formed as solid particles in advance and then dispersed in a dispersion medium (water phase), and 2) heating the ceramides. The ceramide-containing particles can be melted or dissolved in a suitable solvent to form a liquid, then added to the aqueous phase and dispersed, and then cooled to room temperature or the solvent removed. Is formed in the system. Natural ceramides and the like are preferably prepared by dissolving with other oil components or dissolving in an organic solvent.

(Other oil components)
The aqueous cosmetic composition of the present invention is constituted as an oil phase by dispersing ceramide-containing particles in an aqueous phase, but an oil component different from ceramides such as natural ceramide described above in the oil phase ( In the present specification, it is appropriately referred to as other oil component) and / or a solvent, and oil-like dispersed particles containing natural ceramide in the oil component and / or solvent are natural type. The form which exists as ceramide containing particle | grains can also be taken. In addition, when taking this form, the average particle diameter of the ceramide-containing particles in the present invention means the average particle diameter of oil droplet-like dispersed particles containing the ceramide-containing particles.

In the present invention, “other oil component” refers to an oil component that does not separate from ceramides at room temperature, and “solvent” refers to a solvent that can dissolve ceramides, and examples thereof include alcohols. .
Here, there is no restriction | limiting in particular in the other oil component which can be used together in this invention. The other oil component may be, for example, an oil component as an active ingredient added according to the purpose of use of the water-based cosmetic. Also, the dispersion stability, the improvement in the feeling of use on the skin, It may be an oil component used for controlling physical properties. Hereinafter, other oil components that can be used in the present invention will be described. In addition, among the “(2) fatty acid having 10 to 30 carbon atoms or a salt thereof” in the present invention, the fatty acid having 10 to 30 carbon atoms may be contained in the ceramide-containing particles as another oil component. Details of the fatty acid having 10 to 30 carbon atoms or a salt thereof will be described later.

(Oil component as an active ingredient)
In the present invention, it is preferable that a functional functional material for cosmetics, which is insoluble or hardly soluble in an aqueous medium, particularly water, is contained as an oil component. The aqueous cosmetic composition of the present invention includes, for example, functional oil components such as carotenoids, which will be described later, to give the emollient effect, anti-aging effect and antioxidant effect of the aqueous cosmetic composition of the present invention. Can do.
The oil component that can be used in the present invention is not particularly limited as long as it is a component that is insoluble or sparingly soluble in an aqueous medium, particularly in water, but is soluble in an oily medium, but oil-soluble vitamins such as carotenoids and tocopherols. Preferably, a radical scavenger containing sucrose and fats and oils such as coconut oil are used.
The term “insoluble in an aqueous medium” means that the solubility in 100 mL of the aqueous medium is 0.01 g at 25 ° C., and the term “insoluble in an aqueous medium means that the solubility in 100 mL of the aqueous medium is 0. It means exceeding 01 g and 0.1 g or less.

-Carotenoids-
As the oil component as an active ingredient, carotenoids containing natural pigments can be preferably used.
The carotenoids that can be used in the aqueous cosmetic composition of the present invention are yellow to red terpenoid pigments, and include natural products such as plants, algae, and bacteria.
Moreover, it is not limited to the thing of natural origin, Any thing will be contained in the carotenoids in this invention if it can be obtained in accordance with a conventional method. For example, many of the carotenoids described below are produced by synthesis, and many commercially available β-carotene is produced by synthesis.

Examples of carotenoids include hydrocarbons (carotenes) and oxidized alcohol derivatives thereof (xanthophylls).
Examples of carotenoids include actinioerythrol, bixin, canthaxanthin, capsanthin, capsorbin, β-8′-apo-carotenal (apocarotenal), β-12′-apo-carotenal, α-carotene, β-carotene, “carotene” "(Mixtures of α- and β-carotenes), γ-carotene, β-cryptoxanthin, lutein, lycopene, violaxanthin, zeaxanthin, and esters of those containing hydroxyl or carboxyl.

Many of the carotenoids occur naturally in the form of cis and trans isomers, but synthetics are often cis-trans mixtures.
Carotenoids can generally be extracted from plant materials. These carotenoids have a variety of functions, for example, lutein extracted from marigold petals is widely used as an ingredient in poultry food and colors poultry skin and fat and eggs produced by poultry There is a function.

  The carotenoids described above may be contained in the ceramide-containing particles, or may be contained in the aqueous cosmetic separately from the ceramide-containing particles.

-Fats and oils-
Examples of the fats and oils used as other oil components include liquid fats and oils (fatty oils) and solid fats and oils (fats) at room temperature.
Examples of the liquid oil include olive oil, camellia oil, macadamia nut oil, castor oil, avocado oil, evening primrose oil, turtle oil, corn oil, mink oil, rapeseed oil, egg yolk oil, sesame oil, persic oil, wheat germ oil, and sasanca Oil, flaxseed oil, safflower oil, cottonseed oil, eno oil, soybean oil, peanut oil, tea seed oil, kaya oil, rice bran oil, cinnagari oil, Japanese kiri oil, jojoba oil, germ oil, triglycerin, glycerin trioctanoate, Examples include glycerin triisopalmitate, salad oil, safflower oil (safflower oil), palm oil, coconut oil, peanut oil, almond oil, hazelnut oil, walnut oil, and grape seed oil.
Moreover, as the solid fats and oils, beef tallow, hardened beef tallow, beef leg fat, beef bone fat, mink oil, egg yolk oil, pork tallow, horse fat, sheep fat, hardened oil, cocoa butter, palm oil, hardened palm oil, Palm oil, palm hardened oil, owl, owl kernel oil, hardened castor oil and the like can be mentioned.
Among these, coconut oil, which is a medium-chain fatty acid triglyceride, is preferably used from the viewpoints of dispersed particle size and stability in an aqueous cosmetic.

  In the present invention, commercially available products can be used as the fats and oils. Moreover, in this invention, the said fats and oils may be used individually by 1 type, or may be mixed and used.

  Examples of the compound having phenolic OH include polyphenols (for example, catechin), guaiac fat, nordihydroguaiaretic acid (NDGA), gallic acid esters, BHT (butylhydroxytoluene), BHA (butylhydroxyanisole), vitamins E, bisphenols, etc. are mentioned. Examples of gallic acid esters include propyl gallate, butyl gallate, and octyl gallate.

  Examples of the amine compound include phenylenediamine, diphenyl-p-phenylenediamine, and 4-amino-p-diphenylamine, and diphenyl-p-phenylenediamine and 4-amino-p-diphenylamine are more preferable.

  Examples of oil-solubilized derivatives of ascorbic acid and erythorbic acid include stearic acid L-ascorbyl ester, tetraisopalmitic acid L-ascorbyl ester, palmitic acid L-ascorbyl ester, palmitic acid erythorbyl ester, tetraisopalmitic acid erythorbyl ester, etc. Is mentioned.

Among these, vitamin E is particularly preferably used from the viewpoint of excellent safety and antioxidant function.
Vitamin E is not specifically limited, For example, what is chosen from the compound group which consists of tocopherol and its derivative (s), and the compound group which consists of tocotrienol and its derivative (s) can be mentioned. These may be used alone or in combination. Moreover, you may use combining the compound group which consists of a tocophenol and its derivative, and each selected from the compound group which consists of a tocotrienol and its derivative, respectively.

The compound group consisting of tocopherol and its derivatives includes dl-α-tocopherol, dl-β-tocopherol, dl-γ-tocopherol, dl-δ-tocopherol, dl-α-tocopherol acetate, nicotinic acid-dl-α-tocopherol Linoleic acid-dl-α-tocopherol, succinic acid dl-α-tocopherol and the like. Among these, dl-α-tocopherol, dl-β-tocopherol, dl-γ-tocopherol, dl-δ-tocopherol, and a mixture thereof (mixed tocopherol) are more preferable. In addition, as the tocopherol derivative, these acetates are preferably used.
The compound group consisting of tocotrienol and derivatives thereof includes α-tocotrienol, β-tocotrienol, γ-tocotrienol, δ-tocotrienol and the like. In addition, as the tocotrienol derivative, these acetates are preferably used. Tocotrienol is a tocopherol-like compound contained in wheat, rice bran, palm oil, and the like, and has three double bonds in the side chain portion of tocopherol and has excellent antioxidant performance.

  It is preferable that these vitamin Es are contained as oil-soluble antioxidants, particularly in the oil phase of aqueous cosmetics, because they can effectively exhibit the antioxidant function of oil components. Among the above vitamin E, it is more preferable to contain at least one selected from the group of compounds consisting of tocotrienol and derivatives thereof from the viewpoint of the antioxidant effect.

  The content of other oil components such as carotenoids and fats and oils described above can be appropriately set according to the dosage form of the aqueous cosmetic of the present invention.

(2) Fatty acid having 10 to 30 carbon atoms or salt thereof The aqueous cosmetic of the present invention contains fatty acid having 10 to 30 carbon atoms or a salt thereof (hereinafter sometimes referred to as “fatty acid component” as appropriate). . With such a fatty acid component, when preparing an aqueous cosmetic, it is easily dissolved in the system in the mixing step of the oil phase component and the aqueous phase component, so fine ceramide-containing particles contained in the aqueous cosmetic The dispersion stability of can be improved. For this reason, for example, even when transparency is required for an aqueous cosmetic, transparency is not impaired.

When a C10-30 fatty acid is applied as the fatty acid component, the fatty acid is preferably contained as an oil phase component in the aqueous cosmetic and as one of the constituent components of the ceramide-containing particles.
When a fatty acid salt having 10 to 30 carbon atoms (fatty acid salt) is applied, the fatty acid salt is soluble in an aqueous medium, so that it can be used as an aqueous phase component of an aqueous cosmetic. . As a fatty-acid component in this invention, a C10-C30 fatty acid or its salt may be included independently, and you may use both together.

The fatty acid having 10 to 30 carbon atoms may be either a saturated or unsaturated fatty acid.
From the viewpoint of emulsification and dispersion stability, the fatty acid having 10 to 30 carbon atoms is preferably a fatty acid that is liquid at 30 ° C.

  Specifically, as the fatty acid component in the present invention, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, 12-hydroxystearic acid, undecylenic acid, tolic acid, isostearic acid, arachidic acid, behenic acid, Examples thereof include linoleic acid, α-linolenic acid, γ-linolenic acid, arachidonic acid, docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), erucic acid, and the like, and these salts alone or in combination of two or more. Can be used in combination. Among them, from the viewpoint of color, odor, and skin irritation, the fatty acid component in the present invention was selected from the group consisting of lauric acid, isostearic acid, oleic acid, γ-linolenic acid, α-linolenic acid and salts thereof. At least one is preferable, and oleic acid is particularly preferable.

  When applying a fatty acid salt as the fatty acid component, the salt structure constituting the fatty acid salt includes metal salts such as sodium and potassium, basic amino acid salts such as L-arginine, L-histidine and L-lysine, and triethanol. Examples include alkanolamine salts such as amines. The type of salt is appropriately selected depending on the type of fatty acid used and the like, but from the viewpoint of solubility and dispersibility, a metal salt such as sodium is preferable.

The fatty acid component contained in the aqueous cosmetic composition of the present invention may be contained in an amount that allows the ceramides to be satisfactorily dispersed. From the viewpoint of storage stability and transparency, the fatty acid component is 0 with respect to the total mass of the ceramides. The amount is preferably 0.01 times or more and 1.0 times or less, and more preferably 0.05 times or more and 0.5 times or less from the viewpoint of storage stability.
By making the content of the fatty acid component 1.0 times or less with respect to the total mass of the ceramides, excessive fatty acid separation and precipitation can be suppressed, while on the other hand, 0.01 times or more. Therefore, fixing to ceramide is sufficient and preferable.

  Further, from the viewpoint of transparency of the aqueous cosmetic, the content of the fatty acid component is preferably 0.00001% by mass to 3.0% by mass with respect to the total mass of the aqueous cosmetic, and 0.00005% by mass. More preferably, it is 2.0 mass% or less.

(3) Surfactant The aqueous cosmetic of the present invention may contain a surfactant. Here, the surfactant does not include the fatty acid component.
Examples of the surfactant other than the fatty acid component in the present invention include cationic, anionic, amphoteric and nonionic surfactants.

  Examples of nonionic surfactants include glycerin fatty acid ester, organic acid monoglyceride, polyglycerin fatty acid ester, propylene glycol fatty acid ester, polyglycerin condensed ricinoleic acid ester, sorbitan fatty acid ester, sucrose fatty acid ester, polyoxyethylene sorbitan Examples include fatty acid esters. These nonionic surfactants can be contained as an oil phase component in the aqueous cosmetic of the present invention.

  Among these nonionic surfactants, polyglyceric acid fatty acid esters are preferable from the viewpoint of emulsion stability, and in particular, polyglycerin fatty acid esters having an HLB of 10 to 16 (hereinafter referred to as “specific poly-polysaccharide” as appropriate). More preferably, it is referred to as “glycerin fatty acid ester”. The polyglycerin fatty acid ester may be contained in the oil phase.

  Surfactants such as specific polyglycerin fatty acid esters can greatly reduce the interfacial tension of the oil phase / water phase, and as a result, the particle size of the ceramide-containing particles contained in the aqueous cosmetics as the oil phase is reduced. It is preferable in that

  Here, HLB is a balance between hydrophilicity and hydrophobicity that is usually used in the field of surfactants, and a commonly used calculation formula such as the Kawakami formula can be used. In the present invention, the following Kawakami equation is adopted.

HLB = 7 + 11.7 log (M _w / M _O )
Here, M _w molecular weight of the hydrophilic groups, M _O is the molecular weight of the hydrophobic group.

Moreover, you may use the numerical value of HLB described in the catalog etc.
Further, as can be seen from the above formula, a surfactant having an arbitrary HLB value can be obtained by utilizing the additivity of HLB.

  Preferred polyglycerin fatty acid esters include at least one polyglycerin having an average degree of polymerization of 10 and fatty acids having 8 to 18 carbon atoms such as caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid. , Oleic acid, or an ester with linoleic acid is particularly preferable.

Preferred examples of such polyglycerol fatty acid esters include hexaglycerol monooleate, hexaglycerol monopalmitate, hexaglycerol monomyristate, hexaglycerol monolaurate, decaglycerol monooleate, decaglycerol monoester. Examples include stearic acid ester, decaglycerin monopalmitic acid ester, decaglycerin monomyristic acid ester, decaglycerin monolauric acid ester, and the like. These HLBs are 10 or more and 16 or less.
Among these, more preferably, decaglycerol monooleate (HLB = 12), decaglycerol monostearate (HLB = 12), decaglycerol monopalmitate (HLB = 13), decaglycerol monomyristate (HLB = 14), decaglycerin monolaurate (HLB = 16), and the like.
In the present invention, these specific polyglycerin fatty acid esters can be used alone or in combination of two or more.

  As the polyglycerin fatty acid ester, decaglycerin oleic acid ester is most preferable. Examples thereof include decaglycerin monolinoleic acid ester (HLB = 12), decaglycerin monooleic acid ester (HLB = 12), and decaglycerin monoester. Examples include stearic acid ester (HLB = 12), decaglycerin monomyristic acid ester (HLB = 14), and decaglycerin monolauric acid ester (HLB = 15.5).

  As the surfactant in the present invention, one selected from polyglycerin fatty acid esters having an HLB of 10 or more and 16 or less, and 1 selected from polyglycerol fatty acid esters having an HLB having a molecular structure different from that of 5 or more and 15 or less. You may combine with seeds or more. The polyglycerol fatty acid ester having an HLB of 5 or more and 15 or less may be a polyglycerol fatty acid ester included in the above-described polyglycerol fatty acid ester, or may be other polyglycerol fatty acid esters.

  Furthermore, in this invention, the aspect which contains polyglyceryl fatty acid ester whose polymerization degree of decaglycerin oleic acid ester and glycerol is less than 10 and whose carbon number of a fatty acid is 12-18 is preferable as surfactant. . The polyglycerol fatty acid ester having a polymerization degree of glycerol of less than 10 and a fatty acid having 12 to 18 carbon atoms is at least one selected from hexaglycerol fatty acid ester and tetraglycerol fatty acid ester, and its HLB Is more preferably 5.0 or more and 15 or less polyglycerol fatty acid ester.

  Examples of hexaglycerin fatty acid ester and tetraglycerin fatty acid ester that are preferably used in combination with decaglycerin oleate, for example, tetraglycerin monostearate (HLB = 6), tetraglycerin monooleate (HLB = 6), Hexaglycerol monolaurate (HLB = 14.5), hexaglycerol monomyristic ester (HLB = 11), hexaglycerol monostearate (HLB = 9), hexaglycerol monooleate (HLB = 9) It is done.

  In the present invention, when decaglycerin oleate is used in combination with hexaglycerin fatty acid ester and / or tetraglycerin fatty acid ester, the content ratio can be appropriately set according to the application form of the ceramide dispersion. However, the range of (decaglycerin fatty acid ester) / (tetraglycerin fatty acid ester and / or hexaglycerin fatty acid ester) = 1/0 to 1/1 is preferable, more preferably 1 / 0.5, and still more preferably 1. /0.25.

Commercially available products can also be applied as polyglycerin fatty acid esters such as specific polyglycerin fatty acid esters.
Examples of commercially available polyglycerin fatty acid esters include Nikko Chemicals Co., Ltd., NIKKOL DGMS, NIKKOL DGMO-CV, NIKKOL DGMO-90V, NIKKOL DGDO, NIKKOL DGMIS, NIKKOL TGIS, NIKKOL DGGI 1-O, NIKKOL Tetlaglyn 3-S, NIKKOL Tetlagyn 5-S, NIKKOL Tetlagyn 5-O, NIKKOL Hexagin K-1-N, KIKOL Hexagin 1-M S, NIKKOL Hexaglyn 4-B, NIKK OL Hexaglyn 5-S, NIKKOL Hexaglyn 5-O, NIKKOL Hexaglyn PR-15, NIKKOL Decaglyn 1-L, NIKKOL Decaglyn 1-M, NIKKOL Decaglyn 1-SV, NIKKOL Decaglyn 1-50SV, NIKKOL Decaglyn 1-ISV, NIKKOL Decaglyn 1-O, NIKKOL Decaglyn 1-OV, NIKKOL Decaglyn 1-LN, NIKKOL Decaglyn 2-SV, NIKKOL Decaglyn 2-ISV, NIKKOL Decaglyn 3-SV, NIKKOL Decaglyn 3-OV, NIKKOL Decaglyn 5-SV, NIKKOL Decaglyn 5- HS, NIK KOL Decaglyn 5-IS, NIKKOL Decaglyn 5-OV, NIKKOL Decaglyn 5-O-R, NIKKOL Decaglyn 7-S, NIKKOL Decaglyn 7-O, NIKKOL Decaglyn 10-SV, NIKKOL Decaglyn 10-IS, NIKKOL Decaglyn 10-OV, NIKKOL Decaglyn 10-MAC, NIKKOL Decaglyn PR-20,

Ryoto polyglyceride, L-7D, L-10D, M-10D, P-8D, SWA-10D, SWA-15D, SWA-20D, S-24D, S-28D, O, manufactured by Mitsubishi Chemical Foods, Inc. -15D, O-50D, B-70D, B-100D, ER-60D, LOP-120DP, DS13W, DS3, HS11, HS9, TS4, TS2, DL15, DO13, Taiyo Chemical Co., Ltd. Sunsoft Q- 17UL, Sunsoft Q-14S, Sunsoft A-141C, Riem Vitamin Co., Ltd. Poem DO-100, Poem J-0021, etc. are mentioned.

  Among these, preferably, NIKKOL Decaglyn 1-L, NIKKOL Decaglyn 1-M, NIKKOL Decaglyn 1-SV, NIKKOL Decaglyn 1-50SV, NIKKOL Decaglyn 1-ISV, NIKKOL Decaglyn 1-O, NIKKOL Decaglyn 1-OV, NIKKOL Decaglyn 1-LN, Ryoto-polyglycerate L-7D, L-10D, M-10D, P-8D, SWA-10D, SWA-15D, SWA-20D, S-24D, S-28D, O-15D, O -50D, B-70D, B-100D, ER-60D, LOP-120DP.

  Furthermore, examples of other nonionic surfactants include other glycerin fatty acid esters, organic acid monoglycerides, polyglycerin fatty acid esters, propylene glycol fatty acid esters, polyglycerin condensed ricinoleic acid esters, sorbitan fatty acid esters, and sucrose fatty acids. Examples thereof include esters and polyoxyethylene sorbitan fatty acid esters. More preferred are sorbitan fatty acid esters, sucrose fatty acid esters, and polyoxyethylene sorbitan fatty acid esters. These surfactants are not necessarily highly purified by distillation or the like, and may be a reaction mixture.

The sorbitan fatty acid ester preferably has 8 or more carbon atoms, more preferably 12 or more. Preferred examples of sorbitan fatty acid esters include sorbitan monocaprylate, sorbitan monolaurate, sorbitan monostearate, sorbitan sesquistearate, sorbitan tristearate, sorbitan isostearate, sorbitan sesquiisostearate, sorbitan oleate, sorbitan sesquioleate And sorbitan trioleate.
In the present invention, these sorbitan fatty acid esters can be used alone or in combination.

  As a commercial item of sorbitan fatty acid ester, Nikko Chemicals Co., Ltd. make, NIKKOL SL-10, SP-10V, SS-10V, SS-10MV, SS-15V, SS-30V, SI-10RV, SI-10 15RV, SO-10V, SO-15MV, SO-15V, SO-30V, SO-10R, SO-15R, SO-30R, SO-15EX, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Sorgen 30V, 40V, 50V, 90, 110, manufactured by Kao Corporation, Rheodor AS-10V, AO-10V, AO-15V, SP-L10, SP-P10, SP-S10V, SP-S30V, SP-O10V, SP-O30V Etc.

As a sucrose fatty acid ester, those having 12 or more carbon atoms of fatty acids are preferable, and those having 12 to 20 carbon atoms are more preferable.
Preferred examples of sucrose fatty acid esters include sucrose dioleate, sucrose distearate, sucrose dipalmitate, sucrose dimyristic ester, sucrose dilaurate, sucrose monooleate, sucrose Examples include sugar monostearate, sucrose monopalmitate, sucrose monomyristic ester, and sucrose monolaurate. Among these, sucrose monooleate, sucrose monostearate, sucrose Monopalmitate, sucrose monomyristate, and sucrose monolaurate are more preferable.
In the present invention, these sucrose fatty acid esters can be used alone or in combination.

Examples of commercially available sucrose fatty acid esters include Ryoto Sugar Esters S-070, S-170, S-270, S-370, S-370F, S-570, and S- manufactured by Mitsubishi Chemical Foods Corporation. 770, S-970, S-1170, S-1170F, S-1570, S-1670, P-070, P-170, P-1570, P-1670, M-1695, O-170, O-1570, OWA-1570, L-195, L-595, L-1695, LWA-1570, B-370, B-370F, ER-190, ER-290, POS-135, manufactured by Daiichi Kogyo Seiyaku Co., Ltd. , DK Ester SS, F160, F140, F110, F90, F70, F50, F-A50, F-20W, F-10, F-A10E, Cosmelike B-30, S-10, S-50, S-70, S-110, S-160, S-190, SA-10, SA-50, P-10, P-160, M-160, L-10, L-50, L- 160, L-150A, L-160A, R-10, R-20, O-10, O-150 and the like.
Among the above, preferably Leutou Sugar Esters S-1170, S-1170F, S-1570, S-1670, P-1570, P-1670, M-1695, O-1570, L-1695, DK Esters SS, F160, F140, F110, cosmetics S-110, S-160, S-190, P-160, M-160, L-160, L-150A, L-160A, O-150.

The polyoxyethylene sorbitan fatty acid ester preferably has 8 or more carbon atoms, more preferably 12 or more. Moreover, as length (addition mole number) of the ethylene oxide of polyoxyethylene, 2-100 are preferable and 4-50 are more preferable.
Preferable examples of polyoxyethylene sorbitan fatty acid ester include sorbitan polyoxyethylene monocaprylate, sorbitan polyoxyethylene monolaurate, sorbitan polyoxyethylene monostearate, sorbitan polyoxyethylene sesquistearate, sorbitan polyoxyethylene tristearate Sorbitan polyoxyethylene isostearate, sorbitan polyoxyethylene sesquiisostearate, sorbitan polyoxyethylene oleate, sorbitan polyoxyethylene sesquioleate, sorbitan polyoxyethylene trioleate, and the like.
These polyoxyethylene sorbitan fatty acid esters can be used alone or in combination.

  As a commercial item of a polyoxyethylene sorbitan fatty acid ester, Nikko Chemicals Co., Ltd. make, NIKKOL TL-10, NIKKOL TP-10V, NIKKOL TS-10V, NIKKOL TS-10MV, NIKOL TS-106V, NIKKOL TS- 30V, NIKKOL TI-10V, NIKKOL TO-10V, NIKKOL TO-10MV, NIKKOL TO-106V, NIKKOL TO-30V, Leodoll TW-L106, TW-L120, TW-P120, TW-P120, manufactured by Kao Corporation S106V, TW-S120V, TW-S320V, TW-O106V, TW-O120V, TW-O320V, TW-IS399C, Rheodor Super SP-L10, TW-L120, Daiichi Kogyo Seiyaku ( Sorgen TW-20, TW-60V, TW-80V, etc. made by a company company are mentioned.

(4) Polyhydric alcohol The aqueous cosmetic of the present invention preferably contains a polyhydric alcohol from the viewpoint of the particle size, dispersion stability and storage stability of the ceramide-containing particles, and antiseptic properties.
The polyhydric alcohol has a moisturizing function and a viscosity adjusting function. The polyhydric alcohol also has a function of reducing the interfacial tension between water and an oil and fat component, facilitating the widening of the interface, and facilitating the formation of fine and stable fine particles.
From the above, the fact that the aqueous cosmetic contains a polyhydric alcohol can further reduce the particle size of the dispersed particles contained in the aqueous cosmetic and is stable over a long period of time while maintaining the fine particle size. It is preferable from the viewpoint that it can be held.
Moreover, the addition of polyhydric alcohol can lower the water activity of the aqueous cosmetic and suppress the growth of microorganisms.

The polyhydric alcohol that can be used in the present invention is not particularly limited as long as it is a dihydric or higher alcohol.
Examples of the polyhydric alcohol include glycerin, diglycerin, triglycerin, polyglycerin, 3-methyl-1,3-butanediol, 1,3-butylene glycol, isoprene glycol, polyethylene glycol, 1,2-pentanediol, 1,2-hexanediol, propylene glycol, dipropylene glycol, polypropylene glycol, ethylene glycol, diethylene glycol, pentaerythritol, neopentyl glycol, maltitol, reduced starch syrup, sucrose, lactitol, palatinit, erythritol, sorbitol, mannitol, xylitol, xylose Glucose, lactose, mannose, maltose, galactose, fructose, inositol, pentaerythritol, maltotrio Scan, sorbitan, trehalose, starch degradation sugars, starch decomposing sugar reduced alcohol and the like, it can be used in the form of a single or a plurality of kinds of mixtures.

  As the polyhydric alcohol, it is preferable to use a polyhydric alcohol having 3 or more hydroxyl groups in one molecule. Thereby, the interfacial tension between the aqueous solvent and the oil and fat component can be reduced more effectively, and finer and more stable fine particles can be formed. As a result, for example, if the aqueous cosmetic composition of the present invention is applied to the skin, the skin permeability can be made higher.

  Among the polyhydric alcohols that satisfy the above-described conditions, particularly when glycerin is used, the particle size of the dispersed particles in the aqueous cosmetic is smaller, and the particle size is small and stable over a long period of time. It is preferable because it is retained.

The content of the polyhydric alcohol is 1% by mass or more and 20% by mass with respect to the total mass of the aqueous cosmetic from the viewpoint of the viscosity of the nanoceramide dispersion and the composition in addition to the above-mentioned particle size, stability and antiseptic properties. % Or less, more preferably 2% by mass or more and 18% by mass or less, and further preferably 32% by mass or more and 15% by mass or less.
It is preferable that the content of the polyhydric alcohol is 1% by mass or more from the viewpoint that sufficient storage stability and moisture retention can be easily obtained depending on the type and content of the fat and oil component. On the other hand, when the content of the polyhydric alcohol is 20% by mass or more, it causes stinging (feels crisp on the skin) and the like, and therefore it is preferably 20% by mass or less.

(5) Polymer compound The aqueous cosmetic of the present invention may contain a polymer compound. Examples of the polymer compound include a water-soluble polymer compound, an amphiphilic polymer, and a water-insoluble polymer.

  As the water-soluble polymer compound, any of synthetic polymers, natural polymers, and semi-synthetic polymers can be widely used. Particularly preferred are saccharides, proteins and complexes thereof.

Examples of saccharides include, but are not limited to, monosaccharides, disaccharides, oligosaccharides, polysaccharides, dextrins, starch derivatives, gums, mucopolysaccharides, and celluloses.
Among these, representative ones are agarose, arabinose, amylose, amylopectin, acacia gum, gum arabic, arabinogalactan, alkylglycoside, alginic acid, sodium alginate, propylene glycol alginate, aldose, inulin, oligosaccharide, gati gum , Curdlan, carrageenan, galactomannan, galactose, xanthan gum, xylose, xyloglucan, chitin, chitosan, guar gum, cluster dextrin, β-glucan, glucuronic acid, glycogen, glycosaminoglycan, glyceraldehyde, glucosamine, glucose, gluco Mannan, ketose, chondroitin sulfate, psyllium seed gum, gellan gum, cyclodextrin, sucrose, hydroxyethyl Cellulose, hydroxypropylcellulose, carboxymethylcellulose, methylcellulose, cellobiose, sorbitol, deoxyribose, dextrin, invert sugar, starch, soy polysaccharide, sugar alcohol, glycoprotein, tragacanth gum, trehalose, hyaluronic acid, fucose, fructose, pullulan, pectin, Examples include heparin, hemicellulose, maltose, mannitol, mannan, lactose, and ribose, but are not limited thereto.
Among these saccharides, gums and polysaccharides are preferable from the viewpoint of dispersion stability due to increase in viscosity, and xanthan gum, gum arabic, pullulan and the like are more preferable from the viewpoint of stability of carotenoids.

Any kind of protein can be used as long as it is a polymer or oligomer in which amino acids are polymerized by peptide bonds, but it is preferably naturally derived and water-soluble.
Proteins include simple proteins composed of amino acids and complex proteins containing components other than amino acids, and both can be used. Examples of simple proteins include gelatin, casein, fibroin, sericin, keratin, protamine and the like. In addition, complex proteins include glycoproteins that bind to carbohydrates, lipoproteins that bind to lipids, metal proteins that bind to metal ions, nucleoproteins that bind to ribonucleic acid, and phosphates. There are phosphoproteins that are proteins bound to groups.
On the other hand, in general, it is often referred to as a protein raw material, and examples include animal muscle protein, milk protein, egg protein, rice protein, wheat protein (wheat gluten), soy protein, yeast protein, and bacterial protein. .
Such proteins may be used as a mixture.

Moreover, it is also preferable to mix | blend macromolecules in skin, such as collagen, hyaluronic acid, and elastin, in cosmetics.
The polymer compounds as described above can be used alone or in combination of two or more.

(6) Polysaccharide fatty acid ester The aqueous cosmetic of the present invention may contain a polysaccharide fatty acid ester. In general, the emulsion / dispersion such as the aqueous cosmetic of the present invention may be formulated in the form of various organic salts or inorganic salts in order to stably formulate each component having various functions. When the amount of the organic salt or the inorganic salt increases as described above, the salt tends to easily cause a phenomenon such as white turbidity, aggregation, precipitation, thickening, and separation, so-called salting out. In particular, in the case of a formulation that emphasizes transparency, such salting out may impair transparency. When the aqueous cosmetic composition of the present invention contains a polysaccharide fatty acid ester, so-called salting-out is well suppressed even when various organic or inorganic salts are added in addition to dispersion stability. can do.
It is also possible to improve the temporal stability of the aqueous cosmetic such as suppression of precipitation of the ceramide dispersion.

In the polysaccharide fatty acid ester, the polysaccharide part is composed of sugar units such as glucose or fructose having an average degree of polymerization of 2 to 140, disaccharides such as sucrose, oligosaccharides, inulin (from 2 to 60 fructose in glucose). And polysaccharides of hexa- or higher sugars such as starch and dextrin. From the viewpoint of suppressing the salting-out phenomenon (that is, the phenomenon of white turbidity, aggregation, precipitation, thickening, separation) in aqueous cosmetics caused by adding salt, dextrin, inulin or a combination thereof is preferable. More preferably, it is inulin. Inulin is an oligosaccharide having D-fructose as a main component, and a furanoid fructose unit having a structure having β-1,2 linked furanoid fructose and α-D-glucose linked to sucrose at the reducing end is Generally, it is about 2-60.
The fatty acid part that forms the ester with the polysaccharide is preferably a fatty acid having 12 to 18 carbon atoms from the viewpoint of the effect of suppressing salting-out, and caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, Examples include oleic acid, stearic acid, isostearic acid, linoleic acid, linolenic acid, ethylhexanoic acid, behenic acid, and behenic acid.

  Examples of such polysaccharide fatty acid esters include dextrin fatty acid esters, sucrose fatty acid esters, starch fatty acid esters, oligosaccharide fatty acid esters, and inulin fatty acid esters, and inulin fatty acid esters and dextrin fatty acid esters are preferred. Inulin fatty acid esters include inulin octoate, decanoate inulin, inulin laurate, inulin myristate, laurylcarbamate, inulin palmitate, inulin stearate, inulin arachiate, inulin behenate, inulin oleate, 2-ethyl Examples include inulin hexanoate, inulin isomyristate, inulin isopalmitate, inulin isostearate, and inoleate isooleate. As the polysaccharide fatty acid ester of the present invention, inulin stearate, lauryl carbamate, dextrin palmitate, dextrin / octanoic acid and dextrin myristate are preferable from the viewpoint of the stability of aqueous cosmetics, and lauryl carbamine. The acid inulin is most preferred.

  Inulin laurylcarbamate has an HLB value of about 8 and low solubility in oily components, but has good dispersibility, low solubility in water, and aggregates in the aqueous phase. In the oil-in-water emulsion, the inulin skeleton is hydrated, so that the inulin laurylcarbamate is located on the surface of the dispersed particles to form a steric barrier, and the steric barrier disperses in the aqueous phase. An emulsified structure that surrounds the particles is formed.

  Polysaccharide fatty acid ester can be used individually or in combination of 2 or more types. The content of the polysaccharide fatty acid ester can be 0.1 to 2 times the amount of ceramide in the ceramide dispersion, and is 0 from the viewpoint of the stability of the aqueous cosmetic. More preferably, the amount is 5 times or more and 1.5 times or less. In addition, the polysaccharide fatty acid ester is preferably 0.05% by mass or more and 2% by mass or less, more preferably 0.5% by mass or more and 1.5% by mass or less of the total mass of the ceramide dispersion. The effect is sufficiently expected when the amount is 0.05% by mass or more, and the amount of 2% by mass or less is preferable because the ceramide dispersion can be maintained at an appropriate viscosity.

  The polysaccharide fatty acid ester may be added to either the aqueous phase or the oil phase, and can be appropriately selected according to the type of the selected polysaccharide fatty acid ester. For example, inulin laurylcarbamate can be included in the dispersion as an aqueous phase component, and dextrin palmitate can be included in the dispersion as an oil phase component.

(7) Water-soluble organic solvent The aqueous cosmetic of the present invention may contain a water-soluble organic solvent. It is not included in the “oil component” in this specification.
The water-soluble organic solvent in this invention is used for mixing with the aqueous solution mentioned later as an oil phase containing a natural component. This aqueous organic solvent is at the same time the main component of the extract from which natural components are extracted. That is, in the present invention, the natural component is used for mixing with an aqueous solution in a state where it is extracted into an extract containing a water-soluble organic solvent as a main component.

The water-soluble organic solvent used in the present invention refers to an organic solvent having a solubility in water at 25 ° C. of 10% by mass or more. The solubility in water is preferably 30% by mass or more, more preferably 50% by mass or more from the viewpoint of the stability of the finished dispersion.
The water-soluble organic solvent may be used alone or a mixed solvent of a plurality of water-soluble organic solvents. Moreover, you may use as a mixture with water. When a mixture with water is used, the water-soluble organic solvent is preferably contained at least 50% by volume, more preferably 70% by volume or more.

  The water-soluble organic solvent is preferably used to prepare an oil phase by mixing an oil phase component when preparing a ceramide dispersion in a method for producing an aqueous cosmetic described later, and after mixing with an aqueous phase It is preferably removed.

  Examples of such water-soluble organic solvents include methanol, ethanol, 1-propanol, 2-propanol, 2-butanol, acetone, tetrahydrofuran, acetonitrile, methyl ethyl ketone, dipropylene glycol monomethyl ether, methyl acetate, methyl acetoacetate, N -Methylpyrrolidone, dimethyl sulfoxide, ethylene glycol, 1,3 butanediol, 1,4 butanediol, propylene glycol, diethylene glycol, triethylene glycol and the like and mixtures thereof. Among these, when limited to food applications, ethanol, propylene glycol, or acetone is preferable, and ethanol or a mixed solution of ethanol and water is particularly preferable.

(8) Other components In addition to the above-described components, the aqueous cosmetic composition of the present invention includes, for example, various medicinal ingredients and preservatives, depending on the use of the aqueous cosmetic composition, as long as the effects of the present invention are not impaired. In addition, other additives that are usually used for the purpose, such as a colorant, can be used in combination.
Examples of such other additives include humectants such as glycine betaine, xylitol, trehalose, urea, neutral amino acids, basic amino acids, medicinal agents such as allantoin, cellulose powder, nylon powder, cross-linked silicone powder, Organic powders such as cross-linked methylpolysiloxane, porous cellulose powder, and porous nylon powder, inorganic powders such as anhydrous silica, zinc oxide, and titanium oxide, refreshing agents such as menthol and camphor, plant extracts, pH Examples include buffers, antioxidants, ultraviolet absorbers, ultraviolet scattering agents, preservatives, fragrances, bactericides, and dyes.

  In the aqueous cosmetic composition of the present invention, when the ceramide-containing particles are used in the oil phase together with other oil components, the particle size of the dispersed particles contained as the oil phase is a factor depending on the components contained in the aqueous cosmetic composition. In addition, the desired refinement of 150 nm or less was achieved due to factors such as the stirring conditions (shearing force / temperature / pressure) in the method for producing the ceramide dispersion described later, the use conditions of the micromixer, and the ratio of the oil phase to the water phase. Oil phase particles can be obtained.

  The transparency of the aqueous cosmetic of the present invention can be roughly judged by visually observing the appearance, but can generally be judged by the turbidity of the aqueous cosmetic. The turbidity of the aqueous cosmetic can be measured as absorbance at 660 nm at 25 ° C. in a 10 mm cell using a UV-VIVE spectral photometer UV-2550 (manufactured by Shimadzu Corporation). That the aqueous cosmetic composition of the present invention is transparent is set to 0.050 or less as measured by the absorbance at 660 nm. The transparency of the aqueous cosmetic is preferably 0.040 or less.

The pH of the aqueous cosmetic of the present invention is 5 . It is preferably 5 or more and 9 or less, more preferably pH 6 or more and 8.5 or less. By setting the pH of the aqueous cosmetic within this range, an aqueous cosmetic that exhibits good dispersion stability and storage stability is obtained. Various pH adjusters may be used to adjust the pH of the aqueous cosmetic to this range.
The pH adjuster may be added and blended when preparing the oil phase or the aqueous phase so that the pH is within a predetermined range in the production process of the aqueous cosmetic, May be added directly. Usable pH adjusters include various inorganic salts usually used in this field, such as acids such as hydrochloric acid and phosphoric acid and alkalis such as sodium hydroxide, lactic acid-sodium lactate, citric acid-sodium citrate, and succinic acid. -Buffering agents such as sodium succinate can be used.

<Method for producing aqueous cosmetics>
The aqueous cosmetic of the present invention is any method as long as it is composed of a fatty acid or a salt thereof, ceramide-containing particles dispersed in an aqueous phase as an oil phase component, and an aqueous phase component containing at least a natural polysaccharide. May be manufactured.

One preferred method for producing the aqueous cosmetic of the present invention is to disperse a fatty acid or a salt thereof and an oil phase component in an aqueous phase from the viewpoint of forming fine and ceramide-containing particles exhibiting good dispersion stability. The ceramide dispersion containing the prepared ceramide-containing particles is prepared in advance, and then mixed with an aqueous composition containing other essential components or optional components.
When this method is adopted, the aqueous composition can be an aqueous solution containing an aqueous medium such as water as a main component, and can be configured to contain the above-mentioned natural polysaccharides, polyhydric alcohols, and the like. The aqueous composition can be appropriately selected in relation to the aqueous phase component of the ceramide dispersion.
Further, the blending ratio of the ceramide dispersion and the aqueous composition may be mixed at any blending ratio as long as the content of each component described above falls within the range of the content in the above-described aqueous cosmetic. In general, it is preferably 1: 0.1 to 1: 10000, more preferably 1: 0.1 to 1: 1000.

  Hereinafter, the ceramide dispersion that can be used in the preferred method for producing the aqueous cosmetic of the present invention will be described in more detail.

-Ceramide dispersion-
A ceramide dispersion prepared when producing an aqueous cosmetic is a transparent ceramide containing ceramide-containing particles dispersed in an aqueous phase as an oil phase component and a fatty acid component that is an oil phase component or an aqueous phase component It is a dispersion, and can be obtained by a production method including mixing an oil phase component containing at least ceramides and an aqueous phase component at a temperature of 40 ° C. or lower.
According to this method, since the oil phase component and the aqueous phase component are mixed at a temperature of 40 ° C. or lower, the oil phase component dissolves well, and a ceramide dispersion excellent in stability over time and storage stability is obtained. be able to.

  In preparing the oil phase, the above-mentioned water-soluble organic solvent for dissolving ceramides can be preferably used. As the water-soluble organic solvent used for this purpose, those described above can be exemplified as they are.

The mixing of the water phase component and the oil phase component may use a known method such as a high pressure emulsification method that applies a shearing force of 100 MPa or more, or a jet injection method that directly injects the oil phase component into the water phase component. And a method using a micromixer in which the oil phase component and the water phase component are each independently passed through a microchannel having a cross-sectional area of 1 μm ² to 1 mm ² at the narrowest portion, and then the phases are combined and mixed. It is preferable to use from the viewpoint of the particle size, dispersion stability, and storage stability of the ceramide-containing particles.
At this time, the viscosity of the aqueous phase is preferably 30 mPa · s or less from the viewpoint of micronization of the ceramide-containing particles.

  In preparing the ceramide dispersion, the temperature during mixing of the oil phase component and the aqueous phase component is preferably 40 ° C. or lower. Although the temperature of 40 degrees C or less at the time of this mixing should just be achieved when mixing an oil phase component and a water phase component, the area | region set by the applied mixing (emulsification) method can be changed suitably. In the method using a micromixer, the temperature in at least the region immediately before mixing and immediately after dispersion may be 40 ° C. or lower.

  As a method for producing a ceramide dispersion, for example, a) an aqueous phase is prepared using an aqueous medium (such as water) containing a fatty acid salt (if present), and b) an oil phase component containing at least ceramides is used. An oil phase is prepared, and c) The oil phase and the aqueous phase are mixed and dispersed by a method described in detail later using a micromixer, and a ceramide having a volume average particle diameter of 1 nm to 100 nm. There is a step of obtaining a ceramide dispersion (emulsion) containing the kind-containing particles (dispersed particles).

The ratio (mass) of the oil phase and the water phase in the emulsification dispersion is not particularly limited, but the oil phase / water phase ratio (mass%) is preferably 0.1 / 99.9 to 50/50. 0.5 / 99.5-30 / 70 is more preferable, and 1 / 99-20 / 80 is still more preferable.
By setting the oil phase / water phase ratio in the above-mentioned range, it is preferable since the active ingredient is sufficiently contained and practically sufficient emulsion stability can be obtained.

When it is desired to obtain a powdered composition using a ceramide dispersion, a powdery composition is obtained by adding a step of drying the emulsion ceramide dispersion obtained above by spray drying or the like. Can do.
The components contained in the oil phase and the aqueous phase in the method for producing a ceramide dispersion are the same as the components of the ceramide dispersion of the present invention described above, and preferred examples and preferred amounts are also the same, and preferred combinations are more preferred. .

[Micromixer]
In the production method applied to the production of the ceramide dispersion, in order to stably form natural ceramide-containing particles of 1 nm to 100 nm, the oil phase component and the water phase component are each independently formed in the narrowest part. It is preferable to adopt a production method in which the cross-sectional area is combined and mixed after passing through a microchannel having a cross-sectional area of 1 μm ² or more and 1 mm ² or less.
The mixing of the oil phase component and the water phase component is preferably mixing by counterflow collision from the viewpoint of obtaining finer dispersed particles.
The most suitable device for mixing by countercurrent collision is a counter-impact micromixer. The micromixer mainly mixes two different liquids in a minute space, and one liquid is an organic solvent phase containing a functional oil component, and the other is an aqueous phase that is an aqueous solution.
When a micromixer is applied to emulsion preparation with a small particle size, which is one of the microchemical processes, the heat generation is relatively low and the heat generation is small, and the particle size is uniform compared to the usual stirring emulsification dispersion method and high-pressure homogenizer emulsification dispersion. In addition, it is easy to obtain a good emulsion or dispersion having excellent storage stability. This is the most suitable method for emulsification including natural components that are susceptible to thermal degradation.

  An outline of a method of emulsifying or dispersing using a micromixer is to divide an aqueous phase and an oil phase into minute spaces, and to contact or collide the minute spaces. This is clearly different from the membrane emulsification method or microchannel emulsification method, in which only one side is divided into minute spaces and the other is bulky. In fact, only one side is divided into minute spaces. However, the effect as in the present invention cannot be obtained. Known micromixers have various structures. Focusing on the flow and mixing in the microchannel, there can be mentioned two types: a method of mixing while maintaining a laminar flow, and a method of mixing with a turbulent flow. In the method of mixing while maintaining the laminar flow, the size of the channel depth is made larger than the channel width, the boundary area between the two liquids is made as large as possible, and the thickness of both layers is made thin, thereby reducing the mixing efficiency. We are trying to make it. In addition, a method has been devised in which the inlet of the two liquids is divided into a large number and is made into a multilayer flow that flows alternately.

  On the other hand, in the method of mixing by turbulent flow, a method of dividing each liquid into narrow channels and flowing at a relatively high speed is common. There has also been devised a method of ejecting one liquid into the other liquid introduced into a micro space using an arrayed micro nozzle. Moreover, the mixing effect is particularly good in the method of forcibly contacting the liquids flowing at high speed using various means. The former method using laminar flow generally produces large particles but relatively uniform distribution, but the latter method using turbulent flow may give a very fine emulsion and is stable. In many cases, the method using turbulent flow is preferable from the viewpoint of stability and transparency. As a method using turbulent flow, a comb type and a collision type are typical. The comb-shaped micromixer has a structure in which two comb-shaped flow paths are arranged so as to face each other so as to face each other, as represented by IMM.

  A collision type micromixer represented by a KM mixer has a structure that uses kinetic energy to make forced contact. Specifically, the center collision disclosed by Nagasawa et al. (“H. Nagasawa et al, Chem. Eng. Technol, 28, No. 3, 324-330 (2005)”, JP 2005-288254 A). Type micromixer. In the method in which the water phase and the organic solvent phase collide with each other, the mixing time is extremely short, and oil phase droplets are instantly formed. Therefore, it is easy to form a very fine emulsion or dispersion.

  In the present invention, when emulsifying by micromixing with a collision type micromixer, the temperature during emulsification (emulsification temperature) is the temperature of the other microspace of the micromixer from the viewpoint of particle size uniformity of the resulting emulsion (micro Micromixing is preferably performed at a temperature of the micromixing portion of the mixer of 40 ° C. or less, more preferably 0 ° C. to 40 ° C., and particularly preferably 5 ° C. to 30 ° C. By setting the emulsification temperature to 0 ° C. or higher, the main component of the dispersion medium is water, which is preferable because the emulsification temperature can be controlled. It is preferable that the temperature of the microspace of the micromixer is 40 ° C. or less. By setting the temperature to 40 ° C. or less, it is possible to easily control the temperature control, and it is possible to eliminate a micro bumping phenomenon that adversely affects the emulsification performance. More preferably, the heat retention temperature is controlled at a temperature of 35 ° C. or lower.

  In the present invention, the water phase before and after being divided into microspaces of the micromixer, the oil phase, and the micromixer and the microspace of the micromixer are heated above the room temperature, and after micromixing and emulsification It is particularly preferable that the oil-in-water emulsion obtained by the micromixer is cooled to room temperature after being collected.

The cross-sectional area of the narrowest portion of the micro space (flow path) of the micromixer in the present invention is 1 μm ² or more and 1 mm ² or less, and 500 μm ² or more from the viewpoint of refining the emulsion particle size and sharpening the particle size distribution. 50,000 μm ² or less is preferable.
Sectional area of the narrowest part of the fine space of the micromixer used in the aqueous phase in the present invention (the channel), from the viewpoint of mixing stability, 1,000 .mu.m ² or 50,000 ² or less is particularly preferred.
Sectional area of the narrowest part of the fine space of the micromixer used in the oil phase (flow path), from the viewpoint of miniaturization and sharpness of the particle size distribution of the emulsion particle size, and particularly preferably 500 [mu] m ² or more 20,000 ² or less .

In addition, when mixing (emulsified and dispersed) with a micromixer, the flow rate of the oil phase and aqueous phase during emulsification and dispersion varies depending on the micromixer used, but from the viewpoint of refining the emulsion particle size and sharpening the particle size distribution Therefore, the flow rate of the aqueous phase is preferably 10 ml / min or more and 500 ml / min or less, more preferably 20 ml / min or more and 350 ml / min or less, and particularly preferably 50 ml / min or more and 200 ml / min or less.
The flow rate of the oil phase is preferably 1 ml / min or more and 100 ml / min or less, more preferably 3 ml / min or more and 50 ml / min or less from the viewpoint of refining the emulsion particle size and sharpening the particle size distribution, more preferably 5 ml. / Min to 50 ml / min is particularly preferable.

  The value obtained by dividing the flow rate of both phases by the cross-sectional area of the microchannel, that is, the flow rate ratio (Vo / Vw) of both phases, is in the range of 0.05 to 5 in terms of particle refinement and micromixer design. Is preferred. However, Vo is the flow rate of the organic solvent phase containing the water-insoluble natural component, and Vw is the flow rate of the water phase. In addition, the flow rate ratio (Vo / Vw) is 0.1 or more and 3 or less is the most preferable range from the viewpoint of further particle refinement.

Moreover, as a liquid-feeding pressure of a water phase and an oil phase, 0.030 MPa or more and 5 MPa or less and 0.010 MPa or more and 1 MPa or less are preferable, Furthermore, 0.1 MPa or more and 2 MPa or less and 0.02 MPa or more are preferable. 0.5 MPa or less is more preferable, and 0.2 MPa or more and 1 MPa or less and 0.04 MPa or more and 0.2 MPa or less are particularly preferable. By setting the liquid phase feeding pressure to 0.030 MPa to 5 MPa, a stable liquid feeding flow rate tends to be maintained, and by setting the oil phase feeding pressure to 0.010 MPa to 1 MPa, uniform This is preferable because the mixing property tends to be obtained.
In the present invention, a combination of preferable examples of the flow rate, the liquid supply pressure, and the heat retention temperature is more preferable.

Next, the path from when the water phase and oil phase are introduced into the micromixer and discharged as an oil-in-water emulsion is described using an example of a microdevice (FIG. 1) as an example of the micromixer in the present invention. To do.
As shown in FIG. 1, the microdevice 100 includes a supply element 102, a merging element 104, and a discharge element 106 each having a cylindrical shape.
On the surface of the supply element 102 facing the confluence element 104, annular channels 108 and 110 having a rectangular cross section as a flow path of the oil phase or the water phase in the present invention are formed concentrically. The feed element 102 is formed with bores 112 and 114 that penetrate in the thickness (or height) direction to reach the respective annular channels.
The joining element 104 is formed with a bore 116 penetrating in the thickness direction. This bore 116 is such that when the elements are fastened to form the microdevice 100, the end 120 of the bore 116 located in the face of the confluence element 104 facing the supply element 102 opens into the annular channel 108. Yes. In the illustrated embodiment, four bores 116 are formed and are arranged at equal intervals in the circumferential direction of the annular channel 108.

A bore 118 is formed through the confluence element 104 in the same manner as the bore 116. As with the bore 116, the bore 118 is also formed to open to the annular channel 110. The bores 118 are also arranged at equal intervals in the circumferential direction of the annular channel 110, and the bores 116 and the bores 118 are arranged alternately.
Microchannels 124 and 126 are formed on the surface 122 of the merging element 104 facing the discharge element 106. One end of the microchannel 124 or 126 is the opening of the bore 116 or 118, and the other end is the center 128 of the surface 122, and all microchannels extend from the bore toward the center 128; It meets at the center. The cross section of the microchannel may be rectangular, for example.

The discharge element 106 is formed with a bore 130 that passes through the center thereof and penetrates in the thickness direction. Therefore, this bore opens at the center 128 of the confluence element 104 at one end and opens outside the microdevice at the other end.
In the present microdevice 100, fluids A and B supplied from the outside of the microdevice 100 at the ends of the bores 112 and 114 flow into the annular channels 108 and 110 via the bores 112 and 114, respectively.

The annular channel 108 and the bore 116 communicate with each other, and the fluid A flowing into the annular channel 108 enters the microchannel 124 through the bore 116. In addition, the annular channel 110 and the bore 118 communicate with each other, and the fluid B flowing into the annular channel 110 enters the microchannel 126 via the bore 118. The fluids A and B flow into the microchannels 124 and 126, respectively, and then flow toward the center 128 to join.
The merged fluid is discharged as a stream C to the outside of the micro device via the bore 130.

Such a micro device 100 can have the following specifications.
Cross-sectional shape of annular channel 108, width / depth / diameter: rectangular, 1.5 / 1.5 / 25mm
Cross-sectional shape, width, depth, diameter of the annular channel 110: rectangular, 1.5 / 1.5 / 20 mm
Diameter and length of bore 112: 1.5 / 10 mm (circular cross section)
Diameter and length of bore 114: 1.5 / 10 mm (circular cross section)
Diameter and length of bore 116: 0.5 / 4 mm (circular cross section)
Diameter and length of bore 118: 0.5 / 4 mm (circular cross section)
Microchannel 124 cross-sectional shape, width, depth, length: rectangle, cross-sectional area,
350 μm / 100 μm / 12.5 mm / 35000 μm ²
Microchannel 126 cross-sectional shape, width, depth, length: rectangle, cross-sectional area,
50 μm / 100 μm / 10 mm / 5000 μm ²
Diameter and length of bore 130: 500 μm, 10 mm (circular cross section)

  The dimensions of the microchannels (124 and 126 in FIG. 1) where the water phase and the oil phase collide define a preferable range in relation to the flow rates of the water phase and the oil phase.

In the present invention, a micromixer disclosed in JP-A-2004-33901 can also be preferably used.
FIG. 2 is a schematic cross-sectional view of a T-shaped microreactor showing an example of a mixing mechanism using the T-shaped microreactor. FIG. 3 is a conceptual diagram of a T-shaped microreactor showing an example of a mixing mechanism using the T-shaped microreactor.
FIG. 2 shows a cross section of the T-shaped channel 200 of the T-shaped microreactor. In the T-shaped channel 200, the fluid that flows in from the inlet 202 a in the direction of arrow D and the fluid that flows in from the inlet 202 b in the direction of arrow E collide with each other in the center of the T-shaped channel 200. And mixed into fine fluid particles. Fine fluid particles flow out from the outlet 204 in the direction of arrow F. This T-shaped microreactor is useful for mixing when the volume of the flow path is small.

  FIG. 3 shows a fluid mixing mechanism (concept) 300 of another T-shaped microreactor. In the fluid mixing mechanism shown in FIG. 3, fluids flowing out from the two flow paths 302a and 302b collide and mix with each other to form fine fluid particles. That is, on the other hand, the fluid flows into the flow path 302a in the direction of arrow G and flows out in the direction of arrow H. On the other hand, it flows into the flow path 302b in the direction of arrow I and flows out in the direction of arrow J. The fluids flowing out from the flow paths 302a and 302b collide, mix, and scatter in a direction approximately perpendicular to the directions of arrows G to J. The fluid mixing mechanism shown in FIG. 3 collides and mixes the fluid diffused by a technique such as atomization. By this collision / mixing, the fluid becomes finer and a large contact surface can be obtained.

  In the production method applicable to the production of the ceramide dispersion, the water-soluble organic solvent used is preferably removed after emulsification or dispersion through the microchannel. Known methods for removing the solvent include evaporation methods using a rotary evaporator, flash evaporator, ultrasonic atomizer, etc., and membrane separation methods such as ultrafiltration membranes and reverse osmosis membranes. Is preferred.

  Ultrafiltration (UF for short) is the pressure of a stock solution (mixed aqueous solution of water, high molecular weight material, low molecular weight material, colloidal material, etc.) and water injection into a UF device, thereby allowing the stock solution to pass through ( It is a device that can be separated into two systems of solution (low molecular weight material) and concentrated liquid (high molecular weight material, colloidal material) and taken out.

  The ultrafiltration membrane is a typical asymmetric membrane made by the Rob-Three Rayan method. Examples of the polymer material used include polyacrylonitrile, polyvinyl chloride-polyacrylonitrile copolymer, polysulfone, polyether sulfone, vinylidene fluoride, aromatic polyamide, and cellulose acetate. Recently, ceramic films have been used. Unlike the reverse osmosis method and the like, the ultrafiltration method does not perform pretreatment, and therefore fouling in which a polymer or the like is deposited on the membrane surface occurs. For this reason, it is common to periodically wash the membrane with chemicals or warm water. For this reason, the membrane material is required to have resistance to chemicals and heat resistance. There are various types of membrane modules for ultrafiltration membranes: flat membrane type, tubular type, hollow fiber type, and spiral type. The performance index of the ultrafiltration membrane is a fractional molecular weight, and various membranes ranging from 1,000 to 300,000 are commercially available. Examples of commercially available membrane modules include, but are not limited to, Microzer UF (Asahi Kasei Chemicals Corporation), capillary element NTU-3306 (Nitto Denko Corporation), and the like.

For removing the solvent from the obtained emulsion, the material of the membrane is particularly preferably polysulfone, polyethersulfone, or aromatic polyamide from the viewpoint of solvent resistance. As a form of the membrane module, a flat membrane is mainly used on a laboratory scale, but a hollow fiber type and a spiral type are industrially used, but a hollow fiber type is particularly preferable. The molecular weight cut off varies depending on the type of the active ingredient, but usually a molecular weight in the range of 5,000 to 100,000 is used.
The operating temperature can be from 0 ° C. to 80 ° C., but the range of 10 ° C. to 40 ° C. is particularly preferable in consideration of deterioration of the active ingredient.

  Lab-scale ultrafiltration devices include ADVANTEC-UHP (Advantech Co., Ltd.), flow type lab test unit RUM-2 (Nitto Denko Co., Ltd.), etc., using flat membrane modules. Industrially, a plant can be configured by arbitrarily combining the size and number of each membrane module according to the required capacity. As a bench scale unit, RUW-5A (Nitto Denko Corporation) and the like are commercially available.

  In the production method applicable to the ceramide dispersion of the present invention, a step of concentrating the obtained emulsion may be added following the solvent removal. As a concentration method, the same method and apparatus as the solvent removal such as an evaporation method and a filtration membrane method can be used. In the case of concentration, the ultrafiltration membrane method is a preferred method. Although it is preferable if the same membrane as that used for solvent removal can be used, ultrafiltration membranes having different fractional molecular weights can be used if necessary. It is also possible to increase the concentration efficiency by operating at a temperature different from the solvent removal.

  The ceramide dispersion obtained by mixing with the micromixer is an oil-in-water emulsion. In the present invention, the volume average particle diameter (median diameter) of the ceramide-containing particles contained in the ceramide dispersion is 2 nm or more and 150 nm or less. From the viewpoint of transparency of the obtained dispersion, it is more preferably 5 nm or more and 50 nm or less. The particle size of the ceramide-containing particles (dispersed particles) can be measured with a commercially available particle size distribution meter or the like, and details thereof are as described above.

<Uses of water-based cosmetics>
The cosmetic of the present invention may be in any form of general dosage forms known as cosmetics such as lotion, cosmetic liquid, gel, milky lotion, cream, face wash and the like. In order to take advantage of the small particle size of the ceramide-containing particles in the present invention, a highly transparent dosage form is preferable, and a lotion, a cosmetic liquid, and a gel preparation are preferable.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist thereof. Unless otherwise specified, “part” is based on mass.

(Preparation of Ceramide Dispersion-1)
Each component described in the following oil phase liquid 1 composition was prepared by stirring at room temperature for about 30 minutes. In addition, the aqueous phase liquid 1 was prepared by adding inulin lauric carbamate to pure water, heating to about 50 ° C., sufficiently stirring and dissolving, then adding and mixing the remaining components, and adjusting the liquid temperature to 30 ° C.

<1 composition of oil phase liquid>
Ceramide 3 [natural ceramide, specific example 1-5] 0.9 part Ceramide 6 [natural ceramide, specific example 1-7] 1.1 parts oleic acid (melting point: 14 ° C.) 0.4 part ethanol [water-soluble Organic solvent] 97.6 parts

<Aqueous phase 1 composition>
Pure water 96.86 parts Inulin laurylcarbamate 0.29 parts Glycerin 1.43 parts 1,3-butanediol 1.43 parts Sodium hydroxide Suitable amount

  The obtained oil phase liquid 1 (oil phase) and aqueous phase liquid 1 (aqueous phase) were mixed at a ratio (mass ratio) of 1: 7 using a collision type KM micromixer 100/100. Thus, a ceramide dispersion 1 at 30 ° C. was obtained. The conditions for using the micromixer are as follows.

-Microchannel-
Oil phase side microchannel Cross-sectional shape / width / depth / length = rectangle / 70 μm / 100 μm / 10 mm
Water phase side microchannel Cross-sectional shape / width / depth / length = rectangle / 490 μm / 100 μm / 10 mm
-Flow rate-
The aqueous phase is 21.0 ml / min. At a flow rate of 3.0 ml / min. Were introduced at a flow rate of 5 μm and micromixed.

  The obtained ceramide dispersion 1 was repeatedly desolvated using “Evapor (CEP-lab)” manufactured by Okawara Seisakusho until the ethanol concentration became 0.1% by mass or less, so that the ceramide concentration was 1.0 mass. The ceramide dispersion A having a pH of 7.5 was obtained by concentration and adjustment so that the concentration of the ceramide was 7.5%. Here, the ceramide concentration is the content of ceramides based on the total mass of the ceramide dispersion.

(Preparation of Ceramide Dispersion-2)
Each component described in the following oil phase liquid 2 composition was stirred at room temperature for 1 hour to prepare oil phase liquid 2.
Preparation of Ceramide Dispersion-1 Oil phase liquid 1 was changed to oil phase liquid 2, and oil phase liquid 2 (oil phase) and the following aqueous phase liquid 2 were each heated to 40 ° C., otherwise the ceramide dispersion Ceramide dispersion 2 was obtained in the same manner as in Preparation-1. Furthermore, the obtained ceramide dispersion liquid 2 was concentrated and adjusted in the same manner as in Preparation of ceramide dispersion-1 to obtain ceramide dispersion B having a pH of 6.2.

<Oil phase liquid 2 composition>
Ceramide 3 [natural ceramide, specific example 1-5] 0.9 part Ceramide 6 [natural ceramide, specific example 1-7] 1.1 parts isostearic acid (melting point: −10 ° C.) 0.4 part ethanol [water-soluble] Organic solvent] 76.0 parts

<Water phase liquid 2 composition>
Pure water
Sodium hydroxide

(Preparation of ceramide dispersion-3)
In the preparation of ceramide dispersion-2, the oil phase liquid 2 was changed to the following oil phase liquid 3, and the obtained oil phase liquid 2 (oil phase) and water (aqueous phase) were each heated to 30 ° C., and the others Produced ceramide dispersion 3 in the same manner as in Preparation 1 of ceramide dispersion. Furthermore, the obtained ceramide dispersion liquid 3 was concentrated and adjusted in the same manner as in preparation of ceramide dispersion-2 to obtain ceramide dispersion C having pH = 7.3.

<Oil phase liquid 3 composition>
Ceramide 3 [natural ceramide, specific example 1-5] 0.9 part Ceramide 6 [natural ceramide, specific example 1-7] 1.1 parts oleic acid (melting point: 14 ° C.) 0.4 part ethanol [water-soluble Organic solvent] 76.0 parts

[Examples 1 and 2, Reference Example 1 , Comparative Example 1]
(Preparation of aqueous cosmetics)
After mixing and dissolving each component except the ceramide dispersion at room temperature so that the types and amounts described in Table 1 are obtained in the aqueous cosmetic preparation after preparation, the ceramide dispersion is set to the types and amounts described in Table 1. The remaining amount was adjusted with water so as to be 100 parts by mass as a whole.

<Evaluation>

1. Measurement of pH The pH was measured by using a glass electrode pH meter (Horiba, F-54). The results are shown in Table 1 below.

2. Measurement of conductivity The conductivity was measured using an AC two-electrode conductivity meter (F-54, manufactured by Horiba, Ltd.). The results are shown in Table 1 below.

3. Particle Size of Ceramides-Containing Particles The particle size of ceramide-containing particles (or oil droplet-like dispersed particles containing them) in each aqueous cosmetic immediately after preparation is determined using a dynamic light scattering particle size distribution analyzer LB-550. (Horiba Ltd.) was used for measurement. The particle size was measured by diluting with pure water so that the concentration of the ceramide-containing particles was 1% by mass and using a quartz cell. The particle diameter was determined as the median diameter when the sample refractive index was 1.600, the dispersion medium refractive index was 1.333 (pure water), and the viscosity of pure water was set as the viscosity of the dispersion medium. The obtained particle diameter was evaluated according to the following criteria. Δ or higher is a level where there is no practical problem.
○: Less than 30 nm Δ: 30 nm or more and less than 150 nm ×: 150 nm or more

4). Evaluation of stability with time of aqueous cosmetics Evaluation of stability with time was performed by the following method using turbidity.
The turbidity immediately after preparation of each of the aqueous cosmetics of Examples 1 and 2, Reference Example 1 and Comparative Example 1 was measured using a UV-VIVE spectrum photometer UV-2550 (manufactured by Shimadzu Corporation) in a 10 mm cell. The absorbance was measured as 660 nm. (Measurement temperature: 25 ° C)
Furthermore, after repeating each cycle of storing each water-based cosmetic in a thermostatic bath at 60 ° C. for 24 hours and then storing it in a refrigerator at 4 ° C. for 24 hours, returning to 25 ° C. and again turbidity Was measured.
As the change in turbidity of each aqueous cosmetic, the difference between the turbidity after storage over time and the turbidity immediately after preparation was calculated and evaluated according to the following criteria. The results are shown in Table 1 below.
X: Change in turbidity is 0.1 or more (a level at which there is no commercial value as a cosmetic)
(Triangle | delta): The change of turbidity is less than 0.05-0.1 (a level which is somehow acceptable on the commercial value as cosmetics)
○: Change in turbidity is less than 0.05 (although change in turbidity is known, there is no problem in terms of commercial value as a cosmetic)

Each of the water-based cosmetics of the examples contains ceramide-containing particles having a fine particle diameter, and since the change in turbidity is small, it can be seen that the water-based cosmetics have excellent temporal stability. On the other hand, it can be seen that the aqueous cosmetic of Comparative Example 1 is inferior in stability over time.

Moreover, the figure which plotted the pH which the aqueous cosmetic liquid of Examples 1-2, the reference example 1 , and the comparative example 1 shows in FIG. 4 on the horizontal axis, and made electric conductivity (mS / cm) the vertical axis | shaft is shown. As shown in FIG. 4, each of the water-based cosmetics according to the examples having the above excellent effects has a pH and electric conductivity of 6.5 or more and an electric conductivity of 5.0 mS / cm or less. In other words, it was confirmed that the relationship of the formula (A) [the relationship of conductivity (mS / cm) ≦ 2.2 × pH-7], which is a more preferable range of the present invention, was satisfied.

It is a disassembled perspective view of the micro device as an example of a micro mixer. It is a schematic sectional drawing of the T-shaped microreactor which shows an example of the mixing mechanism by a T-shaped microreactor. It is a conceptual diagram of the T-shaped microreactor which shows an example of the mixing mechanism by a T-shaped microreactor. It is the figure which plotted pH which the aqueous cosmetic liquid of Examples 1-2, the reference example 1 , and the comparative example 1 shows on a horizontal axis, and made electric conductivity (mS / cm) a vertical axis | shaft.

Explanation of symbols

100 microdevice 102 supply element 104 confluence element 106 discharge element 124 microchannel 126 microchannel 128 center

Claims (11)

A ceramide-containing particle containing at least a ceramide (excluding glycosphingolipid extracted from konjac koji) , dispersed in an aqueous phase as an oil phase component and having a volume average particle diameter of 2 nm to 150 nm, and carbon An aqueous cosmetic comprising at least a fatty acid of several 10 to 30 or a salt thereof and an electrolyte, having a pH of 6.5 or more and an electric conductivity of 5.0 mS / cm or less. The aqueous cosmetic according to claim 1, wherein the pH and the electrical conductivity (mS / cm) satisfy the relationship of the following formula (A).
Conductivity (mS / cm) ≦ 2.2 × pH-7 Formula (A)   The aqueous cosmetic according to claim 1 or 2, wherein a volume average particle diameter of the particles is 5 nm or more and 100 nm or less.   Furthermore, the aqueous cosmetic of any one of Claims 1-3 containing a polyhydric alcohol.   The aqueous cosmetic according to any one of claims 1 to 4, further comprising a polymer compound.   The aqueous cosmetic according to any one of claims 1 to 5, wherein the fatty acid having 10 to 30 carbon atoms is liquid at 30 ° C.   The fatty acid having 10 to 30 carbon atoms or a salt thereof is at least one selected from the group consisting of lauric acid, isostearic acid, oleic acid, γ-linolenic acid, α-linolenic acid, and salts thereof. The aqueous cosmetic according to any one of claims 6 to 7. It is the manufacturing method of the aqueous cosmetics of any one of Claims 1-7,
Mixing an oil phase component containing at least the ceramide and an aqueous phase component at a temperature of 40 ° C. or lower to obtain a ceramide dispersion;
Mixing the ceramide dispersion with an aqueous composition;
A method for producing a water-based cosmetic comprising:   The method for producing an aqueous cosmetic according to claim 8, comprising dissolving the ceramides in a good solvent for ceramides.   The method for producing an aqueous cosmetic according to claim 9, wherein the good solvent for the ceramide is a water-soluble organic solvent. The mixing of the oil phase component and the water phase component is carried out by combining them after passing each independently through a microchannel having a cross-sectional area of the narrowest portion of 1 µm ² or more and 1 mm ² or less. The manufacturing method of the water-based cosmetics of any one of Claims 8-10.